On 8/1/08, Brian Aker <[EMAIL PROTECTED]> wrote: > > > On Aug 1, 2008, at 3:46 PM, Josh Berkus wrote: > > How would you handle a large set of flags then? BOOL columns? >> > > > We have a BIT type, but it really is an 1 byte int in the memory format > (aka what we pass around). > > It is up to an engine to decide how it wants to store it. Right now in > Drizzle no engine does this (and MyISAM in theory could but it will take > some rework). > > So right now BIT is just an ALIAS really to saying TINYINT. > > The operators though operate on any type.
I've done pretty interesting things with bitstrings due to MySQL's not handling many flags very well, but that's a huge hack and involves hard-coding what each position in the bitstring means. I think for handling, using ENUM/SET is appropriate (though it may also be easy enough to alias BIT to be an ENUM if you really want). As for operators, I'm guessing you mean the ~, !, |, &, <<, >>, and groupwise BIT_AND() and BIT_OR() and BIT_XOR(). Given the complete brokenness in the way the BIT_AND() function handles NULL ( http://bugs.mysql.com/bug.php?id=37754), I doubt very many people use it. And given my experience, very very very few people use bits unless they're flagging something.... ...and even then about 6 months later they realize that they need more than 2 values. I don't believe anyone in Drizzle's target audience is doing bitwise math in the database, including left and right shifts, and especially not the groupwise functions. I can see it coming in handy with -Sheeri
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